{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T12:09:08.010Z","years_from_j2000":26.678,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"hd-152879","name":"54 Her","class":"k4iii_iv_orange_giant","category":"star","object_type":"K4III-IV orange giant","mag":5.35,"mag_band":"V","abs_mag":-0.047,"abs_mag_band":"V","distance_ly":391.5442083213961,"distance_method":"parallax","ra_deg":253.842375,"dec_deg":18.433213,"epoch_ra_deg":254.137995,"epoch_dec_deg":18.389858,"epoch_moved_arcsec":3.079,"pm_ra_mas_yr":-114.79,"pm_dec_mas_yr":11.85,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Hercules","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/hd-152879","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"16554+1826","companions":[{"measured":2016,"magnitude":9.6,"components":"AB","discoverer_code":"BU  954","separation_arcsec":2.4,"position_angle_deg":183},{"measured":2015,"magnitude":12.5,"components":"AC","discoverer_code":"FOX 196","separation_arcsec":88.4,"position_angle_deg":318}],"mass_solar":3.902,"radius_solar":23.903,"spectral_type":"K4III-IV","uncertainties":{"metallicity_fe_h":[0.021,0.021]},"color_index_bv":1.407,"luminosity_solar":90.9494338555295,"metallicity_fe_h":-0.16,"radial_velocity_km_s":12,"spectral_type_source":"SIMBAD (1985ApJS...59...95A, quality C)","surface_gravity_log_g":1.961,"surface_temperature_k":4403,"metallicity_fe_h_source":"Median of 3 spectroscopic determinations in 3 papers, compiled from the literature (PASTEL, Soubiran+ 2016); the error bar is the scatter between them","proper_motion_ra_mas_yr":-114.79,"proper_motion_dec_mas_yr":11.85,"stellar_parameters_method":"Gaia DR3 model fit (GSP-Phot, FLAME; RUWE ≤ 1.4)","bolometric_luminosity_solar":206.1815},"designations":[{"catalog":"Bayer/Flamsteed","designation":"54 Her"},{"catalog":"HD","designation":"HD 152879"},{"catalog":"HIP","designation":"HIP 82802"},{"catalog":"HR","designation":"HR 6293"}],"source":{"id":"hyg","name":"HYG Database v4.1","url":"https://github.com/astronexus/HYG-Database","license":"CC-BY-SA-4.0"},"updated_at":"2026-09-02T19:50:56.720Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}